



@article {2351,
	title = {Surface characterization and cell response of a PLA/CaP glass biodegradable composite material},
	journal = {Journal of Biomedical Materials Research - Part AJ. Biomed. Mater. Res. Part A},
	volume = {85},
	year = {2008},
	note = {Cited By (since 1996): 5Export Date: 21 November 2012Source: ScopusCODEN: JBMRCdoi: 10.1002/jbm.a.31546PubMed ID: 17729262Language of Original Document: EnglishCorrespondence Address: Ginebra, M. P.; Department of Materials Science, Institute of Bioengineering of Catalonia (IBEC), Technical University of Catalonia, Avda Diagonal 647, 08028-Barcelona, Spain; email: maria.pau.ginebra@upc.eduChemicals/CAS: 3 (4,5 dimethyl 2 thiazolyl) 2,5 diphenyltetrazolium bromide, 298-93-1; calcium phosphate, 10103-46-5, 13767-12-9, 14358-97-5, 7758-87-4; osteocalcin, 136461-80-8; polylactic acid, 26100-51-6; Alkaline Phosphatase, EC 3.1.3.1; Bone Substitutes; calcium phosphate, 10103-46-5; Calcium Phosphates; Lactic Acid, 50-21-5; Osteocalcin, 104982-03-8; poly(lactic acid), 26100-51-6; PolymersReferences: Barrows, T., Degradable implants materials: A review of synthetic absorbable polymers and their applications (1986) Clin Mater, 1, pp. 233-267;Ciccone, W., Motz, C., Bentley, C., Tasto, J., Bioabsorbable implants in orthopaedics: New developments and clinical applications (2001) J Am Acad Orthop Surg, 9, pp. 280-288; 
Dunn, R.L., Clinical applications and update on the poly (alpha-hydroxy acids) (1995) Biomedical Applications of Synthetic Biodegradable Polymers, pp. 17-31. , Hollinger JO, editor, Boca Raton: CRC Press;; 
Middleton, J.C., Tipton, A.J., Synthetic biodegradable polymers as orthopedic devices (2000) Biomaterials, 21, pp. 2335-2346; 
B{\"o}stman O Current concepts review. Absorbable implants for fracture fixation. J Bone Joint Surgery 1991;73A:148-153Ashammakhi, N., Suuronen, R., Tiainen, J., Tormala, P., Waris, T., Spotlight on naturally absorbable osteofixation devices (2003) J Craniofac Surg, 14, pp. 247-259; 
Hou, Q.P., Grijpma, D.W., Feijen, J., Porous polymeric structures for tissue engineering prepared by a coagulation, compression moulding and salt leaching technique (2003) Biomaterials, 24, pp. 1937-1947; 
Kellomaki, M., Niiranen, H., Puumanen, K., Ashammakhi, N., Waris, T., Tormala, P., Bioabsorbable scaffolds for guided bone regeneration and generation (2000) Biomaterials, 21, pp. 2495-2505; 
Mooney, D.J., Park, S., Kaufmann, P.M., Sano, K., Mcnamara, K., Vacanti, J.P., Langer, R., Biodegradable sponges for hepatocyte transplantation (1995) J Biomed Mater Res, 29, pp. 959-965; 
Ragel, C.V., Vallet-Regi, M., In vitro bioactivity and gentamicin release from glass-polymer-antibiotic composites (2000) J Biomed Mater Res, 51, pp. 424-429; 
Kohn, J., Langer, R., Bioabsorbable and bioerodible materials (1996) Biomaterials Science, pp. 64-72. , Ratner BD, Hoffman A, Schoen F, Lemons J, editors, New York: Academic Press;; 
Navarro, M., Ginebra, M.P., Clement, J., Martinez, S., Avila, G., Planell, J.A., Physicochemical degradation of titania-stabilized soluble phosphate glasses for medical applications (2003) J Am Ceram Soc, 86, pp. 1345-1352; 
Navarro, M., Ginebra, M.P., Planell, J.A., Barrias, C.C., Barbosa, M., In vitro degradation behavior of a novel bioabsorbable composite material based on PLA and a soluble CaP glass (2005) Acta Biomaterialia, 1, pp. 411-419; 
Stephansson, S.N., Byers, B.A., Garcia, A.J., Enhanced expression of the osteoblastic phenotype on substrates that modulate fibronectin conformation and integrin receptor binding (2002) Biomaterials, 23, pp. 2527-2534; 
Keselowsky, B.G., Collard, D.M., Garcia, A.J., Surface chemistry modulates fibronectin conformation and directs integrin binding and specificity to control cell adhesion (2003) J Biomed Mater Res A, 66, pp. 247-259; 
Beumer, G., van Blitterswijk, C., Bakker, D., Ponec, M., Cell-seeding and in vitro biocompatibility evaluation of polymeric matrices of PEO/PBT copolymers and PLLA (1993) Biomaterials, 14, pp. 598-604; 
Ishaug, S., Yaszemski, M., Bizios, R., Mikos, A., Osteoblast function on synthetic biodegradable polymers (1994) J Biomed Mater Res, 28, pp. 1445-1453; 
Navarro, M., Ginebra, M.P., Planell, J.A., Cellular response to calcium phosphate glasses with controlled solubility (2003) J Biomed Mater Res A, 67, pp. 1009-1015; 
Huffman, K.R., Casey, D.J., Effect of carboxyl end groups on hydrolysis of polyglycolic acid (1985) J Polym Sci A: Polym Chem, 23, pp. 1939-1954; 
Ishaug-Riley, S.L., Okun, L.E., Prado, G., Applegate, M.A., Ratcliffe, A., Human articular chondrocyte adhesion and proliferation on synthetic biodegradable polymer films (1999) Biomaterials, 20, pp. 2245-2256; 
Park, A., Griffith, L., In vitro cell response to differences in poly-1-lactide crystallinity (1996) Biomaterials, 31, pp. 117-130; 
Cai, K.Y., Yao, K.D., Lin, S.B., Yang, Z.M., Li, X.Q., Xie, H.Q., Poly (D, L-lactic acid) surfaces modified by silk fibroin: Effects on the culture of osteoblast in vitro (2002) Biomaterials, 23, pp. 1153-1160; 
Lopes, M.A., Monteiro, F.J., Santos, J.D., Serro, A.P., Saramago, B., Hydrophobicity, surface tension, and zeta potential measurements of glass-reinforced hydroxyapatite composites (1999) J Biomed Mater Res, 45, pp. 370-375; 
Vogler, E.A., Structure and reactivity of water at biomaterial surfaces (1998) Adv Colloid Interface Sci, 74, pp. 69-117; 
Vogler, E.A., Interfacial chemistry in biomaterials science (1993) Surfactant Science Series, pp. 183-250. , Berg JC, editor. Wettability, Marcel Dekker, New York; 
Charles-Harris, M., Navarro, M., Engel, E., Aparicio, C., Ginebra, M.P., Planell, J., A Surface characterisation of completely degradable composite scaffolds (2005) J Mater Svi: Mater Med, 16, pp. 1125-1130; 
Lampin, M., WarocquierClerout, R., Legris, C., Degrange, M., SigotLuizard, M.F., Correlation between substratum roughness and wettability, cell adhesion, and cell migration (1997) J Biomed Mater Res, 36, pp. 99-108; 
Khang, G., Jeon, J.H., Lee, L.W., Cho, S.C., Lee, H.B., Cell and platlet adhesion on plasma glow discharge-treated poly(lactide-co-glycolide) (1997) Biomed Mater Engl, 7, pp. 357-368; 
Webb, K., Hlady, V., Tresco, P.A., Relative importance of surface wettability and charged functional groups on NIH 3T3 fibroblast attachment, spreading, and cytoskeletal organization (1998) J Biomed Mater Res, 41, pp. 422-430; 
Owen, T.A., Aronow, M., Shalhoub, V., Barone, L.M., Wilming, L., Tassinari, M.S., Progressive development of the rat osteoblast phenotype in vitro - Reciprocal relationships in expression of genes associated with osteoblast proliferation and differentiation during formation of the bone extracellular-matrix (1990) J Cell Physiol, 143, pp. 420-430; 
Lian, J.B., Stein, G.S., Concepts of osteoblast growth and differentiation - Basis for modulation of bone cell-development and tissue formation (1992) Crit Rev Oral Biol Med, 3, pp. 269-305; 
Quarles, L.D., Yohay, D.A., Lever, L.W., Caton, R., Wenstrup, R.J., Distinct proliferative and differentiated stages of murine Mc3T3-E1 cells in culture - An in vitro model of osteoblast development (1992) J Bone Miner Res, 7, pp. 683-692; 
Boyan, B.D., Dean, D.D., Lohmann, C.H., Cochran, D.L., Sylvia, V.L., Schwartz, Z., The titanium-bone cell interface in vitro: The role of the surface in promoting osteointegration (2001) Titanium in Medicine, pp. 562-585. , Brunette D, Tengvall P, Textor M, Thomsen P, editors, Berlin: Springer-Verlag;; 
Gronowicz, G., McCarthy, M.B., Ahmad, M., Direct integrin-mediated attachment of human osteoblasts to implants (1996) J Bone Miner Res, 11, pp. S323; 
Boyan, B.D., Hummert, T.W., Kieswetter, K., Schraub, D., Dean, D.D., Schwartz, Z., Effect of titanium surface characteristics on chondrocytes and osteoblasts in vitro (1995) Scan Electron Microsc, 5, pp. 323-335; 
Martin, J.Y., Schwartz, Z., Hummert, T.W., Schraub, D.M., Simpson, J., Lankford, J., Effect of titanium surface-roughness on proliferation. Differentiation, and protein-synthesis of human osteoblast-like cells (MG63) (1995) J Biomed Mater Res, 29, pp. 389-401
},
	month = {2008///},
	pages = {477 - 486},
	abstract = {Bioabsorbable materials are of great interest for bone regeneration applications, since they are able to degrade gradually as new tissue is formed. In this work, a fully biodegradable composite material containing polylactic acid (PLA) and calcium phosphate (CaP) soluble glass particles has been characterized in terms of surface properties and cell response. Cell cultures were performed in direct contact with the materials and also with their extracts, and were evaluated using the MTT assay, alkaline phosphatase activity, and osteocalcin measurements. The CaP glass and PLA were used as reference materials. No significant differences were observed in cell proliferation with the extracts containing the degradation by-products of the three materials studied. A relation between the materials wettability and the material-cell interactions at the initial stages of contact was observed. The most hydrophilic material (CaP glass) presented the highest cell adhesion values as well as an earlier differentiation, followed by the PLA/glass material. The incorporation of glass particles into the PLA matrix increased surface roughness. SEM images showed that the heterogeneity of the composite material induced morphological changes in the cells cytoskeleton. {\textcopyright} 2007 Wiley Periodicals, Inc.},
	keywords = {3 (4,5 dimethyl 2 thiazolyl) 2,5 diphenyltetrazolium bromide, Absorbable Implants, alkaline phosphatase, article, Biodegradable composite materials, biodegradable implant, Biodegradation, Bone, Bone Regeneration, Bone Substitutes, calcium phosphate, Calcium phosphates, cell adhesion, Cell culture, cell function, cell interaction, Cell Line, cell proliferation, Cell response, Composite materials, cytoskeleton, glass, human, human cell, Humans, hydrophilicity, hydrophobicity, In vitro test, Lactic Acid, materials testing, Osteoblasts, osteocalcin, polylactic acid, Polymers, scanning electron microscope, Surface analysis, Surface Properties, wettability},
	isbn = {15493296 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-42149187233\&partnerID=40\&md5=8942b2e00b94ff0f723261e1893d04b5},
	author = {Navarro, M. and Engel, E. and Planell, J.A. and Amaral, I. and Barbosa, M. and Ginebra, M.P.}
}
@book {2493,
	title = {Effect of the Solvents on the Solution Mixture Derived Polylactide/hydroxyapatite Composites},
	series = {Key Engineering MaterialsKey Eng Mat},
	volume = {254-256},
	year = {2004},
	note = {Conference code: 62053Cited By (since 1996): 1Export Date: 21 November 2012Source: ScopusCODEN: KEMAELanguage of Original Document: EnglishCorrespondence Address: Weng, W.; Dept. of Mat. Sci. and Engineering, Zhejiang University, Hangzhou 310027, China; email: wengwj@zju.edu.cnReferences: Hench, L.L., (1998) Journal of American Ceramic Society, 81, p. 1705;Wang, M., (2003) Biomaterials, 24, p. 2133; 
Hao, J., Yuan, M., Deng, X., (2001) Biomaterials, 22, p. 2867; 
Ignjatovic, N., Tomic, S., Dakic, M., Miljkovic, M., Plavsic, M., Uskokovic, D., (1999) Biomaterials, 20, p. 809; 
Misra, D.N., (1988) Langmuir, 4, p. 953; 
Dean, J.A., (1999) Lange{\textquoteright}s Handbook of Chemistry (15th Edition), , McGraw-HILL, INC. New York
},
	month = {2004///},
	pages = {477 - 480},
	address = {Porto},
	abstract = {Polylactide/hydroxyapatite composites were prepared by a solution mixture method. Chloroform and tetrahydrofuran were used as solvents. The effect of the solvents on the polylactide/hydroxyapatite composites was investigated by TEM, mechanical properties, sedimentation time and UV-Vis transmission spectra. The results indicate that the polylactide/hydroxyapatite prepared using tetrahydrofuran as solvent has better dispersion of the hydroxyapatite filler in the matrix and larger bend strength than the one using chloroform as solvent. This is ascribed to the proper interaction between the solvent and hydroxyapatite filler.},
	keywords = {Bend strength, Composite, Composite materials, dispersion, Dispersions, Fillers, Heat treatment, Hydroxvapatite, hydroxyapatite, Polarity, polylactide, Sedimentation, Solutions, Solvent, Solvents, transmission electron microscopy, Ultraviolet radiation},
	isbn = {10139826 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0346885571\&partnerID=40\&md5=4f0c563b563f23ea5102e4ef36cfd243},
	author = {Li, Y. and Weng, W. and Cheng, K. and Du, P. and Shen, G. and Han, G. and Lopes, M.A. and Santos, J.D.},
	editor = {Barbosa M.A. and Monteiro F.J. and Correia R. and Leon B.}
}
@book {2522,
	title = {Production of porous biomaterials based on glass-reinforced hydroxyapatite composites},
	series = {Key Engineering MaterialsKey Eng Mat},
	volume = {230-232},
	year = {2002},
	note = {Conference code: 60281Cited By (since 1996): 5Export Date: 21 November 2012Source: ScopusCODEN: KEMAELanguage of Original Document: EnglishCorrespondence Address: Prado da Silva, M.H.; Instituto de Engenharia Biomedica, Laborat{\'o}rio de Biomaterials, Rua do Campo Alegre 823, PT-4150-180 Porto, PortugalReferences: Lemos, A.F., Ferreira, J.M.F., (2000) Materials Science and Engineering, 11, pp. 35-40;Saggio-Woyansky, J., Scott, C.E., Minnear, W.P., (1992) Amer. Cer. Society Bulletin, 71 (11), pp. 1674-1682; 
Lopes, M.A., Santos, J.D., Monteiro, F.J., Ohtsuki, C., Osaka, A., Kaneko, S., Inouue, H., (2001) J. Biom. Mater. Res., 54, pp. 463-469; 
Knowles, J.C., Santos, J.D., Hastings, G.W., (2000) Sintered Hydroxyapatite Composition and Method for the Preparation thereof, , Patent number WO0068164
},
	month = {2002///},
	pages = {483 - 486},
	address = {Coimbra},
	abstract = {In this study, porous GR-HA composites were produced using a calcium-phosphate glass with the composition, in mol\%, 75P                        2O
                        5-15CaO-10CaF
                        2. The composites were obtained by wet mixing 4.0\% (w/w) of the glasses with hydroxyapatite (HA) powder (batch P120) (Plasma Biotal; Tideswell, U.K.), pressing and sintering. Two different organic additives were used as pore formers: potato starch and almond crust. This processing route was effective in producing a homogeneous microstructure of equiaxed grains. The bulk density of the samples decreased with the volume fraction increase in the content of pore formers. Scanning electron microscopy and mercury porosimetry analyses showed to be complementary techniques in characterising the pore size and distribution.
},
	keywords = {Biomaterials, Composite materials, glass, Glass-reinforced hydroxyapatite composites, GR-HA Composites, hydroxyapatite, Macroporous Bioceramics, Mercury (metal), Microstructure, Organic Additives, Pore size, Porous materials, Powders, Pressing (forming), Scanning electron microscopy, Sintering, Starch},
	isbn = {10139826 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0036432238\&partnerID=40\&md5=9af5590c70f4defe5e87b9a72042e11b},
	author = {Prado da Silva, M.H. and Lemos, A.F. and Ferreira, J.M.F. and Lopes, M.A. and Santos, J.D.},
	editor = {Vieira T.}
}
@article {2569,
	title = {Glass-reinforced hydroxyapatite composites: Fracture toughness and hardness dependence on microstructural characteristics},
	journal = {BiomaterialsBiomaterials},
	volume = {20},
	year = {1999},
	note = {Cited By (since 1996): 65Export Date: 21 November 2012Source: ScopusCODEN: BIMADdoi: 10.1016/S0142-9612(99)00112-XPubMed ID: 10535820Language of Original Document: EnglishCorrespondence Address: Santos, J.D.; Laboratorio de Biomateriais, Instituto de Engenharia Biomedica, INEB, Rua do Campo Alegre 823, 4150 Porto, PortugalChemicals/CAS: alpha-tricalcium phosphate; Biocompatible Materials; calcium phosphate, 10103-46-5; Calcium Phosphates; Composite Resins; dicalcium phosphate anhydrous, 7757-93-9; Durapatite, 1306-06-5; monocalcium phosphate; tetracalcium phosphateReferences: Akao, M., Aoki, H., Kato, K., Mechanical properties of sintered hydroxyapatite for prosthetic applications (1981) J Mater Sci, 16, pp. 809-812;Martin, R.I., Brown, P.W., Mechanical properties of hydroxyapatite formed at physiological temperature (1995) J Mater Sci Mater Med, 6, pp. 138-143; 
Aoki, H., (1994) Medical Applications of Hydroxyapatite, pp. 90-173. , Tokyo, Missouri, USA: Ishiyaku EuroAmerica Inc; 
Yamamuro, T., Hench, L., Wilson, J., Calcium phosphate and hydroxyapatite ceramics (1990) In: Handbook of Bioactive Ceramics, 2, pp. 273-335. , editors. Florida: CRC Press Inc; 
Cao, W., Hench, L.L., Bioactive materials (1996) Ceramics Int, 22, pp. 493-507; 
Davidge, R.W., (1979) Mechanical Behaviour of Ceramics, , Cambridge: Cambridge University Press; 
Orange, G., Liang, K.M., Crack resistance and fracture toughness of alumina and zirconia ceramics: comparisons of notched-beam and indent techniques (1988) Science of Ceramics, 14, pp. 709-714. , Amsterdam: Elsevier; 
Niihara, K., Morena, R., Hasselman, D.P.H., Evaluation of K IC of brittle solids by the indentation method with low crack-to-indent ratios (1982) J Mater Sci Lett, 1, pp. 13-16; 
Evans, G., Fracture toughness: The role of indentation techniques (1979) Fracture Mechanics Applied to Brittle Materials ASTM STP 678, pp. 112-135. , S.W. Freiman. Blasksbaurg: American Society for Testing and Materials; 
Anstis, G.R., Chantikul, P., Lawn, B.R., Marshall, D.B., A critical evaluation of indentation techniques for measuring fracture toughness: I. Direct crack measurements (1981) J Am Ceram Soc, 64 (9), pp. 533-538; 
Chantikul, P., Anstis, G.R., Lawn, B.R., Marshall, D.B., A critical evaluation of indentation techniques for measuring fracture toughness: II. Strength method (1981) J Am Ceram Soc, 64 (9), pp. 539-543; 
Evans, G., Charles, E.A., Fracture toughness determinations by indentation (1976) J Am Ceram Soc, 59 (78), pp. 371-372; 
Marion, R.H., Use of indentation fracture to determine fracture toughness (1979) Fracture Mechanics Applied to Brittle Materials, ASTM STP 678, pp. 103-111. , S.W. Freiman. Blasksbaurg: American Society for Testing and Materials; 
Knowles, J.C., Talal, S., Santos, J.D., Sintering effects in a glass reinforced hydroxyapatite (1996) Biomaterials, 17, pp. 1437-1442; 
Lopes, M.A., Monteiro, F.J., Santos, J.D., Glass reinforced hydroxyapatite composites: Secondary phase proportions and densification effects on biaxial bending strength (1999) J Appl Biomater, , in press; 
Lopes, M.A., Knowles, J.C., Kuru, L., Santos, J.D., Monteiro, F.J., Flow cytometry for assessing biocompatibility (1998) J Biomed Mater Res, 4, pp. 649-656; 
Santos, D., Knowles, J.C., Reis, R.L., Monteiro, F.J., Hastings, G.W., Microstructural characterisation of glass reinforced hydroxyapatite composites (1994) Biomaterials, 15 (1), pp. 5-10; 
Lopes, M.A., Santos, J.D., Monteiro, F.J., Knowles, J.C., Glass reinforced hydroxyapatite: A comprehensive study of the effect of glass composition on the crystallography of the composite (1998) J Biomed Mater Res, 39 (2), pp. 244-251; 
Laugier, M.T., New formula for indentation toughness in ceramics (1987) J Mater Sci Lett, 6, pp. 355-356; 
Ampiro, R., (1958) Acta Anat, 3, p. 161; 
De With, G., Van Dijk, H.J.A., Hattu, N., Prijs, K., Preparation, microstructure and mechanical properties of dense polycrystalline hydroxyapatite (1981) J Mater Sci, 16, pp. 1592-1598; 
German, R.M., (1985) Liquid Phase Sintering, , Oxford: Plenum Press; 
Rice, R.W., Microstructure dependence of mechanical behaviour (1977) Treatise on Materials Science and Technology, 11. , MacCrone R.K. New York: Academic Press; 
Rice, R.W., Grain size and porosity dependence of ceramic fracture energy and toughness at 22{\textdegree}C (1996) J Mater Sci, 31, pp. 1969-1983; 
Lankford, J., Indentation microfracture in the Palmqvist crack regime: Implications for fracture toughness evaluation by the indentation method (1982) J Mater Sci Lett, 1, pp. 493-495; 
Li, Z., Ghosh, A.A., Kobayashi, A.S., Bradt, R.C., Indentation fracture toughness of sintered silicon carbide in the Palmqvist crack regime (1989) J Am Ceram Soc, 72 (6), pp. 904-911; 
Lawn, R., Marshall, D.B., Hardness, toughness and brittleness: An indentation analysis (1980) J Am Ceram Soc, 62 (78), pp. 347-350; 
Niihara, K., A fracture mechanics analysis of indentation-induced Palmqvist crack in ceramics (1983) J Mater Sci Lett, 2, pp. 221-223; 
Plannel, J.A., Vallet-Regi, M., Fernandez, E., Driessens, F.C.M., Fracture toughness evaluation of sintered hydroxyapatite (1994) Bioceramics 7, Proceedings of the Seventh International Symposium on Ceramics in Medicine, pp. 18-22. , In: Andersson OH, Yli-Urpo A, editors; 
Aoki, H., (1991) Science and Medical Applications of Hydroxyapatite, , Japanese Association of Apatite Science. Tokyo: Takayama Press System Center Co. Inc; 
Hauber, R.A., Anderson, R.M., Engineering properties of glass-matrix composites In: Ceramics and Glasses, Engineered Materials Handbook, pp. 858-869. , USA: ASM Publication; 
Barsoum, M., Mechanical properties: Fast fracture (1997) Fundamentals of Ceramics. Series in Materials Science and Engineering, pp. 391-439. , New York: McGraw-Hill; 
Slosarczyk, A., Bia Oskorski, J., Hardness and fracture toughness of dense calcium-phosphate based materials (1998) J Mater Sci Mater Med, 9, pp. 103-108
},
	month = {1999///},
	pages = {2085 - 2090},
	publisher = {Elsevier Science Ltd},
	abstract = {Fracture toughness and hardness properties of CaO-P                        2O
                        5 glass-reinforced hydroxyapatite composites have been assessed using indentation techniques and results calculated according to Laugier and Evans{\textquoteright} equations. Both properties showed to be dependent upon several microstructural characteristics, namely residual porosity and the percentage of secondary β and α tricalcium phosphate phases in the structure of the composites. Composites presented a Palmqvist-type indentation crack system, which is the specific crack system addressed by Laugier{\textquoteright}s approach. Fracture toughness determinations according to Evan{\textquoteright}s equation, which is a universal one and adapted to both median and Palmqvist crack systems, did not correlate well with Laugier determinations. Copyright (C) 1999 Elsevier Science Ltd.
Fracture toughness and hardness properties of CaO-P
                        2O
                        5 glass-reinforced hydroxyapatite composites have been assessed using indentation techniques and results calculated according to Laugier and Evans{\textquoteright} equations. Both properties showed to be dependent upon several microstructural characteristics, namely residual porosity and the percentage of secondary β and α tricalcium phosphate phases in the structure of the composites. Composites presented a Palmqvist-type indentation crack system, which is the specific crack system addressed by Laugier{\textquoteright}s approach. Fracture toughness determinations according to Evan{\textquoteright}s equation, which is a universal one and adapted to both median and Palmqvist crack systems, did not correlate well with Laugier determinations.
},
	keywords = {article, Biocompatible Materials, Biomaterials, calcium phosphate, Calcium phosphates, ceramics, Composite materials, Composite Resins, Cracks, Durapatite, Evan{\textquoteright}s equation, Fracture toughness, glass, hardness, hydroxyapatite, Hydroxyapatite-glass composites, Indentation techniques, Kinetics, Laugier equations, material state, mechanical stress, Microscopy, Electron, Scanning, Microstructure, Palmqvist crack systems, Phosphate minerals, porosity, priority journal, Stress, Mechanical, tensile strength, Tricalcium phosphate},
	isbn = {01429612 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0033231746\&partnerID=40\&md5=55066a0fcfb28ee10321c5820371f75a},
	author = {Lopes, M.A. and Monteiro, F.J. and Santos, J.D.}
}
@article {2572,
	title = {Glass-reinforced hydroxyapatite composites: Secondary phase proportions and densification effects on biaxial bending strength},
	journal = {Journal of Biomedical Materials ResearchJ. Biomed. Mater. Res.},
	volume = {48},
	year = {1999},
	note = {Cited By (since 1996): 28Export Date: 21 November 2012Source: ScopusCODEN: JBMRBdoi: 10.1002/(SICI)1097-4636(1999)48:5<734::AID-JBM20>3.0.CO;2-2PubMed ID: 10490690Language of Original Document: EnglishCorrespondence Address: Santos, J.D.; INEB-Instituto Engenharia Biomedica, Laboratorio de Biomateriais, Rua do Campo Alegre, 823, 4150 Porto, PortugalChemicals/CAS: alpha-tricalcium phosphate; Biocompatible Materials; calcium phosphate, 10103-46-5; Calcium Phosphates; dicalcium phosphate anhydrous, 7757-93-9; Hydroxyapatites; monocalcium phosphate; tetracalcium phosphateReferences: Yamamuro, Y., Hench, L.L., Wilson, J., (1990) CRC Handbook of Bioactive Ceramics, , Boca Raton, FL: CRC;Rice, R.W., Microstructure dependence of mechanical behaviour (1977) Treatise on Materials Science and Technology, 11. , MacCrone RK, editor. New York: Academic; 
Rice, R.W., Grain size and porosity dependence of ceramic fracture energy and toughness at 22{\textdegree}C (1996) J Mat Sci, 31, pp. 1969-1983; 
Santos, J.D., Knowles, J.C., Reis, R.L., Monteiro, F.J., Hastings, G.W., Microstructural characterisation of glass reinforced hydroxyapatite composites (1994) Biomaterials, 15, pp. 5-10; 
Lopes, M.A., Knowles, J.C., Santos, J.D., Monteiro, F.J., Olsen, I., Flow cytometry for assessing biocompatibility (1998) J Biomed Mater Res, 41, pp. 649-656; 
Wayne, S.F., Buljan, S.T., Microstructure and wear resistance of silicon nitride composites (1994) Friction and Wear of Ceramics, p. 261. , Jahanmir S, editor. New York: Marcel Dekker; 
Kaysser, W.A., Sprissler, M., Handwerker, C.A., Blendell, J.E., Effect of liquid phase on the morphology of grain growth of alumina (1987) J Am Ceram Soc, 70, pp. 339-343; 
Lopes, M.A., Santos, J.D., Monteiro, F.J., Knowles, J.C., Glass reinforced hydroxyapatite: A comprehensive study of the effect of glass composition on the crystallography of the composite (1998) J Biomed Mater Res, 39, pp. 244-251; 
Soltesz, U., Ritcher, H., Kienzler, R., The concentric-ring test and its applications for determining the surface strength of ceramics (1987) High Tech Ceram, pp. 149-159. , Amsterdam: Elsevier; 
Murtage, B., (1981) Advance Linear Programming, , New York: McGraw-Hill; 
Cha{\textquoteright}tal, V., (1990) Linear Programming, , New York: Freeman; 
Davidge, R.W., (1986) Mechanical Behaviour of Ceramics, , Cambridge: Cambridge Univ Press; 
German, R.M., (1985) Liquid Phase Sintering, , New York: Plenum; 
Akao, M., Aoki, H., Kato, K., Mechanical properties of sintered hydroxyapatite for prosthetic applications (1981) J Mater Sci, 16, pp. 809-812; 
Fanovich, M.A., Lopes, J.M.P., Influence of temperature and additives on the microstructure and sintering behaviour of hydroxyapatites with different Ca/P ratios (1998) J Mat Sci Mat Med, 9, pp. 53-60; 
Jarcho, M., Bolen, C.H., Bobik, J., Kay, J.F., Doremus, R.H., Hydroxyapatite synthesis and characterisation in dense polycrystalline form (1976) J Mat Sci, 11, pp. 2027-2035; 
Van Landuyt, P., Li, F., Keustermans, J.P., Streydio, J.M., Delnnay, F., Munting, E., The influence of high sintering temperatures on the mechanical properties of hydroxyapatite (1995) J Mat Sci Mat Med, 6, pp. 8-13; 
Aoki, H., (1991) Science and Medical Applications of Hydroxyapatite, , Japanese Association of Apatite Layer; 
Chawla, K.K., (1993) Ceramic Matrix Composites, , London, UK: Chapman Hall; 
Barsoum, M., Fundamentals of Ceramics, , New York: McGraw-Hill; 1997
},
	month = {1999///},
	pages = {734 - 740},
	publisher = {John Wiley \& Sons Inc},
	abstract = {CaO-P                        2O
                        5 glasses with additions of MgO and CaF
                        2 were used as a sintering aid of hydroxyapatite, and glass-reinforced hydroxyapatite composites obtained. Glasses promoted significant changes in the microstructure of the composites, namely with the formation of tricalcium phosphate secondary phases, β and α-TCP. Quantitative phase analysis was performed by the Rietveld method using General Structure Analysis Software. Grain size measurements were carried out on SEM photomicrographs, using a planimetric procedure according to ASTM E 112-88. Flexural bending strength was determined from concentric ring-on-ring testing. Flexural bending strength (FBS) of glass-reinforced hydroxyapatite composites was found to be about twice or three times higher than that of unreinforced hydroxyapatite and tended to depend more on porosity and β and α-TCP secondary phases, rather than on grain size. Traces of α-tricalcium phosphate significantly enhanced the strength of the composites. Using the rule of mixtures to estimate the zero porosity bending strength, the Duckworth-Knudsen model applied to the composites gave a porosity correction factor, b, with a value of 4.02. Weibull statistics were also used to analyze biaxial strength data and the level of reinforcement obtained by comparing failure probability for the composites and for the unreinforced hydroxyapatite. Lower activation energies for grain growth were observed for the composites compared to unreinforced hydroxyapatite, which should be attributed to the presence of a liquid glassy phase that promotes atomic diffusion during the sintering process.
CaO-P
                        2O
                        5 glasses with additions of MgO and CaF
                        2 were used as a sintering aid of hydroxyapatite, and glass-reinforced hydroxyapatite composites obtained. Glasses promoted significant changes in the microstructure of the composites, namely with the formation of tricalcium phosphate secondary phases, β and α-TCP. Quantitative phase analysis was performed by the Rietveld method using General Structure Analysis Software. Grain size measurements were carried out on SEM photomicrographs, using a planimetric procedure according to ASTM E 112-88. Flexural bending strength was determined from concentric ring-on-ring testing. Flexural bending strength (FBS) of glass-reinforced hydroxyapatite composites was found to be about twice or three times higher than that of unreinforced hydroxyapatite and tended to depend more on porosity and β and α-TCP secondary phases, rather than on grain size. Traces of α-tricalcium phosphate significantly enhanced the strength of the composites. Using the rule of mixtures to estimate the zero porosity bending strength, the Duckworth-Knudsen model applied to the composites gave a porosity correction factor, b, with a value of 4.02. Weibull statistics were also used to analyze biaxial strength data and the level of reinforcement obtained by comparing failure probability for the composites and for the unreinforced hydroxyapatite. Lower activation energies for grain growth were observed for the composites compared to unreinforced hydroxyapatite, which should be attributed to the presence of a liquid glassy phase that promotes atomic diffusion during the sintering process.
},
	keywords = {article, atom, Bending (deformation), Biocompatibility, Biocompatible Materials, Biomaterials, calcium fluoride, calcium phosphate, Calcium phosphates, Composite materials, Densification, Dental application, dentistry, Duckworth-Knudsen model, glass, Glass reinforced hydroxyapatite, Humans, hydroxyapatite, Hydroxyapatite-glass composites, Hydroxyapatites, Implants (surgical), Magnesium Oxide, mathematical analysis, Mechanical strength, Mechanics, Medical applications, Microstructure, orthopedics, Phase composition, physical chemistry, porosity, Scanning electron microscopy, Strength of materials, tensile strength, Tissue, Tricalcium phosphate},
	isbn = {00219304 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032868650\&partnerID=40\&md5=e6fa831a838301db0336e9010a0800dd},
	author = {Lopes, M.A. and Monteiro, F.J. and Santos, J.D.}
}
@article {2575,
	title = {Hydrophobicity, surface tension, and zeta potential measurements of glass-reinforced hydroxyapatite composites},
	journal = {Journal of Biomedical Materials ResearchJ. Biomed. Mater. Res.},
	volume = {45},
	year = {1999},
	note = {Cited By (since 1996): 46Export Date: 21 November 2012Source: ScopusCODEN: JBMRBdoi: 10.1002/(SICI)1097-4636(19990615)45:4<370::AID-JBM12>3.0.CO;2-0PubMed ID: 10321710Language of Original Document: EnglishCorrespondence Address: Santos, J.D.; INEB, University of Porto, Rua do Campo Alegre, 823, 4150 Porto, PortugalChemicals/CAS: Biocompatible Materials; Calcium Phosphates; Hydroxyapatites; Proteins; VitronectinReferences: Yamamuro, Y., Hench, L.L., Wilson, J., (1990) CRC Handbook of Bioactive Ceramics, , Boca Raton, FL: CRC Press;Santos, J.D., Knowles, J.C., Reis, R.L., Monteiro, F.J., Hastings, G.W., Microstructural characterization of glass reinforced hydroxyapatite composites (1994) Biomaterials, 15, pp. 5-10; 
Aoki, H., Medical applications of hydroxyapatite (1991) Science and Medical Applications of Hydroxyapatite, pp. 1-214. , Aoki H, Sawai K, editors. Tokyo: Takyama Press System Center; 
Akao, M., Aoki, H., Kato, K., Mechanical properties of sintered hydroxyapatite for prosthetic applications (1981) J Mater Sci, 16, pp. 809-812; 
Davies, J.E., The importance and measurement of surface charge species in cell behaviour at the biomaterial interface (1988) Surface Characterization of Biomaterials, pp. 219-234. , Ratner BD. New York: Elsevier; 
Ratner, B.D., Biomaterial surfaces (1987) J Biomed Mater Res Appl Biomat, 21, pp. 59-90; 
Manson, S.R., Harker, L.A., Ratner, B.D., Hoffman, A.S., Evaluation of artificial surfaces with a non human primate model of arterial thrombosis (1980) J Lab Clin Med, 95, pp. 289-304; 
Grinnell, F., Milamand, M., Srere, P.A., Studies on cell adhesion (1972) Arch biochem biophys, 153, pp. 193-198; 
Chang, S.K., Hum, O.S., Moscarello, Ma., Neumann, A.W., Zing, W., Leutheusser, M.J., Ruegsegger, B., Platelet adhesion to solid surfaces: The effect of plasma proteins and substrate wettability (1997) Med Progr Technol, 5, pp. 57-66; 
Agathopoulos, S., Nikolopoulos, P., Determination of the energy of the interactions oxides and biological liquids (1995) Fourth Euro Ceramics, 8, pp. 319-324. , Ravaglioli A, editor; 
Lapin, M., Warocquier-Cl{\'e}rout, R., Legris, C., Degrange, M., Luizard, M.F.S., Correlation between roughness and wettability, cell adhesion and cell migration (1997) J Biomed Mater Res, 36, pp. 99-108; 
Williams, D.F., Bagnall, R.D., Adsorption of proteins on polymers and its role in the response of soft tissue (1998) Fundamental Aspects of Biocompatibility, 2, pp. 113-127. , Williams DF, editor. Boca Raton, FL: CRC Press; 
Dimitrov, S., Krachevsky, P.A., Nikolov, A.D., Noshi, H., Matsumoto, M., Contact angle measurements with sessile drops and bubbles (1991) J Colloid Interface Sci, 145, pp. 279-282; 
Adamson, W., (1990) Physical chemistry of surfaces. 5th edition, pp. 4-52. , New York: Wiley; 
Young, T., (1835) Miscellaneous Works, 1, p. 418. , Peacock G, editor London: Murray; 
Young, T., (1805) Philos Trans R Soc Lond, 95, p. 65; 
Correia, N.T., Ramos, J.M., Saramago, B., Calado, J., Estimation of the surface tension of a solid: Application to a liquid crystalline (1997) J Colloid Interface Sci, 189, pp. 361-369; 
Owens, D.K., Wendt, R.D., Estimation of the surface free energy of polymers (1969) J Appl Polym Sci, 13, p. 1741; 
Schrader, M.E., Young dupr{\'e} revisited (1995) Langmuir, 11, p. 3585; 
Kowalchuk, R.M., Pollack, S.R., Ducheyne, P., King, L.A., Particle microelectrophoresis of calcium-deficient hydroxyapatite: Solution composition and kinetics effects (1993) J Biomed Mater Res, 27, pp. 783-790; 
Ducheyne, P., Kim, C.S., Pollack, S.R., The effect of phase differences on the time dependent variation of the zeta potential of hydroxyapatite (1992) J Biomed Mater Res, 26, pp. 147-168; 
Suzuki, T., Nishizawa, K., Yokogawa, Y., Kameyama, T., Time-dependent variation of the surface structure of bioceramics in tissue culture medium and the effect on adhesiveness of cells (1996) J Ferment Bioeng, 81, pp. 226-232; 
Susuki, T., Yamamoto, T., Yoriyama, M., Kameyama, T., Surface instability of calcium phosphates ceramics in tissue culture medium and the effect on adhesion and growth of anchorage-dependent animal cells (1997) J Biomed Mater Res, 34, pp. 507-517; 
Hay, H., (1991) Cell Biology of Extracellular Matrix. 2nd Edition, pp. 127-129. , New York: Plenum Press; 
Seiffert, D., Detection of vitronectin in mineralized bone matrix (1986) J Histochem Cytochem, 44, pp. 275-280; 
Rodan, G.A., Introduction to bone biology (1992) Bone, 12, p. 53; 
Young, M.E., Kerr, J.M., Ibaraki, K., Heegaard, A.M., Gehron, R.P., Structure, expression and regulation of the major matrix proteins of bone (1992) Clin Orthop Rel Res, 281, p. 275; 
Formigli, L., Zecchi, S., Benvenuti, S., Brandi, M.L., Cell to cell interaction on bone tissue (1992) Ann NY Acad Sci, 673, p. 120; 
Underwound, P.A., Bennett, F.A., A comparison of the biological activities of the cell-adhesive proteins vitronectin and fibronectin (1989) J Cell Sci, 93, pp. 641-649; 
Hayman, E.G., Pierschbacher, M.D., Suzuki, S., Ruoslahti, E., Vitronectin: A major cell attachment-promoting protein in foetal bovine serum (1985) Exp Cell Res, 160, pp. 245-250; 
Lopes, Ma., Knowles, J.C., Santos, J.D., Monteiro, F.J., Olsen, I., Flow cytometry for assessing biocompatibility (1998) J Biomed Mater Res, 41, pp. 649-656; 
Lopes, Ma., Santos, J.D., Monteiro, F.J., Knowles, J.C., Glass reinforced hydroxyapatite: A comprehensive study of the effect of glass composition on the crystallography of the composite (1998) J Biomed Mater Res, 39, pp. 244-251; 
Cheng, P., Li, D., Boruvka, L., Rotenberg, Y., Neumann, A.W., Automation of axisymmetric drop shape analysis for measurements of interfacial tensions and contact angles (1990) Colloids Surf, 43, pp. 151-167; 
Cheng, P., Neumann, A.W., Computational evaluation of axisymmetric drop shape analysis-profile (ADSA-P) (1992) Colloids Surf, 62, pp. 297-306; 
Saramago, B., Teixeira, M.J., Rosa, M.E., Bordadao, J.C., Influence of the wetting properties of polymeric adhesives on the mechanical behaviour of cork agglomerates (1996) A Adhes Sci Technol, 10, pp. 1111-1127; 
Voigt, A., Thiel, O., Williams, D., Policova, Z., Zingg, W., Neumann, A.W., Asymmetric drop shape analysis (ADSA) applied to protein solution (1991) Colloid Surf, 58, p. 315; 
Williams, R.L., Hunt, J.A., Tengvall, P., Fibroblast adhesion onto methyl-silica gradients with and without preadsorbed proteins (1995) J Biomed Mater Res, 29, pp. 1545-1555; 
Hench, L.L., Ethridge, E.C., (1982) Biomaterials: An Interfacial Approach, , New York: Academic Press; 
Horbert, T.A., Brash, J.L., Proteins at interfaces. II. Fundamentals and applications (1994) ACS Symposium, 602, pp. 1-23. , Chapter 1, Chapter 7; 
Vogler, E.A., Interfacial chemistry in biomaterials science (1993) Wettability, 49, pp. 183-250. , Berg JC, editor New York: Marcel Dekker; Chapter 4
},
	month = {1999///},
	pages = {370 - 375},
	publisher = {John Wiley \& Sons Inc},
	abstract = {Wettability and zeta potential studies were performed to characterize the hydrophobicity, surface tension, and surface charge of P                        2O
                        5-glass- reinforced hydroxyapatite composites. Quantitative phase analysis was performed by the Rietveld method using GSAS software applied to X-ray diffractograms. Surface charge was assessed by zeta potential measurements. Protein adsorption studies were performed using vitronectin. Contact angles and surface tensions variation with time were determined by the sessile and pendent drop techniques, respectively, using ADSA-P software. The highest (- 18.1 mV) and lowest (-28.7 mV) values of zeta potential were found for hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), respectively, with composite materials presenting values in between. All studied bioceramic materials showed similar solid surface tension. For HA and β-TCP, solid surface tensions of 46.7 and 45.3 mJ/m
                        2, respectively, were obtained, while composites presented intermediate surface tension values. The dispersive component of surface tension was the predominant one for all materials studied. Adhesion work values between the vitronectin solution and HA and β- TCP were found to be 79.8 and 88.0 mJ/m
                        2, respectively, while the 4.0 wt \% glass composites showed slightly lower values than the 2.5 wt \% ones. The presence of β-TCP influenced surface charge, hydrophobicity, and protein adsorption of the glass-reinforced HA composites, and therefore indirectly affected cell-biomaterial interactions.
The hydrophobicity, surface tension, and surface charge of P
                        2O
                        5-glass-reinforced hydroxyapatite (HA) composites were characterized through wettability and zeta potential studies. The highest and lowest values of zeta potential were found for HA and β-TCP. All studied bioceramic materials showed similar solid surface tension. The presence of β-TCP indirectly affected cell-biomaterial interactions.
},
	keywords = {Adhesion, Adsorption, Algorithms, article, Biocompatible Materials, biomaterial, Biomaterials, Bone, Calcium Compounds, calcium phosphate, Calcium phosphates, Cells, Chemical analysis, Chemistry, Physical, Composite materials, Contact angle, glass, Glass reinforced hydroxyapatite composites, hydrophobicity, hydroxyapatite, Hydroxyapatite-glass composites, Hydroxyapatites, implant, Implants (surgical), Interfacial energy, Phosphorus Compounds, Protein adsorption, Proteins, Surface charge, Surface Properties, surface property, Surface tension, Tricalcium phosphate, Vitronectin, wettability, X-Ray Diffraction, Zeta potential},
	isbn = {00219304 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0033563979\&partnerID=40\&md5=3807a20c608ec3dcf8cce1d48213c1a3},
	author = {Lopes, M.A. and Monteiro, F.J. and Santos, J.D. and Serro, A.P. and Saramago, B.}
}
@article {2619,
	title = {Characterization of apatite layer formation on P                    2O
                    5-CaO, P
                    2O
                    5-CaO- Na
                    2O, and P
                    2O
                    5-CaO-Na
                    },
	journal = {Journal of Biomedical Materials ResearchJ. BIOMED. MATER. RES.},
	volume = {31},
	year = {1996},
	note = {Cited By (since 1996): 20Export Date: 21 November 2012Source: ScopusCODEN: JBMRBdoi: 10.1002/(SICI)1097-4636(199608)31:4<481::AID-JBM7>3.0.CO;2-HPubMed ID: 8836844Language of Original Document: EnglishCorrespondence Address: Jha, L.J.; IRC in Biomedical Materials, Queen Mary and Westfield College, Mile End Road, London E1 4NS, United KingdomChemicals/CAS: HydroxyapatitesReferences: Hyakuna, K., Yamamuro, T., Kotoura, Y., Oka, M., Kokubo, T., Kushitani, H., Surface reactions of calcium phosphate ceramics to various solutions (1990) J. Biomed. Mater. Res., 24, pp. 471-488;Ebisawa, Y., Kokubo, T., Ohura, K., Yamamuro, T., Bioactivity of CaO{\textperiodcentered}SiO 2-based glasses: In vitro evaluation (1990) J. Mater. Sci.: Mater. Med., 1, pp. 239-244; 
Kokubo, T., Kushitani, H., Ohtsuki, C., Sakka, S., Yamamuro, T., Chemical reaction of bioactive glass and glass ceramics with a simulated body fluid (1992) J. Mater. Sci.: Mater. Med., 3, pp. 79-83; 
Li, P., Yang, Q., Zhang, F., Kokubo, T., The effect of residual glassy phase in a bioactive glass-ceramic on the formation of its surface apatite layer in vitro (1992) J. Mater. Sci.: Mater. Med., 3, pp. 452-456; 
Ohtsuki, C., Aoki, Y., Kokubo, T., Yamamuro, T., Nakamura, T., Characterization of apatite layer formed on bioactive glass-ceramic A-W (1992) Bioceramics, 5, pp. 87-94. , T. Yamamuro, T. Kokubo, and T. Nakamura (eds.), Kokunshi Kankokai, Japan; 
Kokubo, T., Kushitani, H., Ohtsuki, C., Sakka, S., Effects of ions dissolved from bioactive glass-ceramic on surface apatite formation (1993) J. Mater. Sci.: Mater. Med., 4, pp. 1-4; 
Kohri, M., Miki, K., Waite, D., Nakajima, H., Okabe, T., In vitro stability of biphasic calcium phosphate ceramics (1993) Biomaterials, 14, pp. 299-304; 
Andersson, O.H., Kangasniemi, I., Calcium phosphate formation at the surface of bioactive glass in vitro (1991) J. Biomed. Mater. Res., 25, pp. 1019-1030; 
Kokubo, T., Kushitani, H., Sakka, S., Kitsugi, T., Yamamuro, T., Solutions able to reproduce in vivo surface-structure changes in bioactive glass-ceramic A-W (1990) J. Biomed. Mater. Res., 24, pp. 721-734; 
Santos, J.D., Knowles, J.C., Hastings, G.W., Bonfield, W., "Sintered hydroxyapatite compositions and method for the preparation thereof," British Patent No. 9,213,774.4 (1993)Santos, J.D., Reis, R.L., Knowles, J.C., Hastings, G.W., Monteiro, F.J., Microstructural characterisation of glass-reinforced hydroxyapatite composites (1994) Biomaterials, 15, pp. 5-10; 
Santos, J.D., Knowles, J.C., Monteiro, F.J., Hastings, G.W., Development of a glass reinforced hydroxyapatite with enhanced mechanical properties: Physical properties and in vitro studies (1992) Bioceramics, 5, pp. 35-41. , T. Yamamuro, T. Kokubo, and T. Nakamura (eds.), Kokunshi Kankokai, Japan; 
Knowles, J.C., Abrahams, I., Bonfield, W., Effect of reinforcing glass composition on phase transformation and crystallographic parameters in hydroxyapatite (1993) Bioceramics, 6, pp. 191-196. , P. Ducheyne and D. Christiansen (eds.), Butterworth Heinemann, New York; 
Knowles, J.C., Bonfield, W., Development of a glass reinforced hydroxyapatite with enhanced mechanical properties. The effect of glass composition on mechanical properties and its relationship to phase changes (1993) J. Biomed. Mater. Res., 27, pp. 1591-1598; 
Burnie, J., Gilchrist, T., Controlled release glass (C.R.C.) - A new biomaterial (1983) Ceramics in Surgery, pp. 169-176. , P. Vincenzini (ed.), Elsevier, Amsterdam; 
Santos, J.D., Jha, L.J., Monteiro, F.J., Study of surface modifications by x-ray photoelectron spectroscopy on glass reinforced hydroxyapatite composites in a simulated physiological solution (1995) Biomaterials, 16, pp. 521-526; 
Rehman, I., Hench, L.L., Bonfield, W., Comparison of hydroxycarbonate apatite layers on bioactive glasses with human bone (1993) Bioceramics, 6, pp. 123-128. , P. Ducheyne and D. Christiansen (eds.), Butterworth Heinemann, New York; 
Landis, W.J., Martin, J.R., X-ray photoelectron spectroscopy applied to gold-decorated mineral standards of biological interest (1984) J. Vac. Sci. Technol., A2, p. 1108; 
Swift, P., Adventitious carbon - The panacea for energy referencing? (1982) Surface Interface Anal., 4, pp. 47-51; 
Clark, D.T., Thomas, H.R., Applications of ESCA to polymer chemistry. XVII. Systematic investigation of the core levels of single homopolymers (1978) J. Polym. Sci., Polym. Chem. Ed., 16, pp. 791-820; 
Verhoeven, J.A., Van Doveren, H., An XPS investigation of the interface of methane, ethyne, ethene, and ethane with barium surface (1982) Surface Sci., 123, pp. 369-383
},
	month = {1996///},
	pages = {481 - 486},
	publisher = {John Wiley \& Sons Inc},
	abstract = {P                        2O
                        5-based glass hydroxyapatite (HA) composites denoted HA-2 oxide, HA-3 oxide, and HA-4 oxide, were immersed in Hank{\textquoteright}s balanced salt solution for a period of 1, 2, 3, and 4 weeks at 37{\textdegree}C in nonagitated condition for in vitro evaluation. A surface layer was precipitated on the composites that was analyzed using scanning electron microscopy (SEM), X-ray photoelecton spectroscopy, and thin film X-ray diffractometry (TF-XRD). SEM micrographs showed complete coverage of the composite surface by crystallites after immersion of 1 week in the solution, which grew thicker with respect to immersion time. The binding energies measured by XPS indicated apatite formation and the presence of carbonate on the composite surface, showing the newly formed layer was a carbonated apatite. Confirmation of the formed apatite layer was obtained by TF-XRD.
                        2O
                        5-based glass hydroxyapatite (HA) composites denoted HA-2 oxide, HA-3 oxide, and HA-4 oxide, were immersed in Hank{\textquoteright}s balanced salt solution for a period of 1, 2, 3, and 4 weeks at 37{\textdegree}C in nonagitated condition for in vitro evaluation. A surface layer was precipitated on the composites that was analyzed using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, and thin film X-ray diffractometry (TF-XRD). SEM micrographs showed complete coverage of the composite surface by crystallites after immersion of 1 week in the solution, which grew thicker with respect to immersion time. The binding energies measured by XPS indicated apatite formation and the presence of carbonate on the composite surface, showing the newly formed layer was a carbonated apatite. Confirmation of the formed apatite layer was obtained by TF-XRD.
},
	keywords = {Apatite, article, binding affinity, Biomaterials, bone strength, Calcium Compounds, Carbonates, Ceramic materials, Characterization, chemical composition, Composite materials, Crystallites, electron microscopy, glass, Glass hydroxyapatite composites, Hank balanced salt solution, hydroxyapatite, Hydroxyapatites, immersion, Microscopy, Electron, Scanning, Molecular Structure, Oxides, prosthesis material, Scanning electron microscopy, scanning tunneling microscopy, Spectrum Analysis, Thin film X ray diffractometry, Thin films, X ray diffraction, X ray diffraction analysis, X ray photoelectron spectroscopy, X-Ray Diffraction},
	isbn = {00219304 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0030222031\&partnerID=40\&md5=1cba84bf7d0e93a4e3a3808849398c78},
	author = {Jha, L.J. and Santos, J.D. and Knowles, J.C.}
}
@article {2627,
	title = {Granules of osteoapatite and glass-reinforced hydroxyapatite implanted in rabbit tibiae},
	journal = {Journal of Materials Science: Materials in MedicineJ. MATER. SCI. MATER. MED.},
	volume = {7},
	year = {1996},
	note = {Cited By (since 1996): 16Export Date: 21 November 2012Source: ScopusCODEN: JSMMELanguage of Original Document: EnglishCorrespondence Address: Afonso, A.; Faculty of Dental Medicine, University of Porto, Rua Dr Roberto Frias, 4200 Porto, PortugalChemicals/CAS: calcium phosphate, 10103-46-5, 13767-12-9, 14358-97-5, 7758-87-4; hydroxyapatite, 1306-06-5, 51198-94-8; magnesium, 7439-95-4; potassium, 7440-09-7; sodium, 7440-23-5References: Ravaglioli, A., Krajewski, A., (1992) Bioceramics-materials, Properties and Applications, p. 100. , Chapman \& Hall, London;Cranin, A.N., Ronen, E., Puntoff, R.S.H., Tobim, G., Dibeling, J.B., (1988) J. Biomed. Mater. Res., 22, p. 1165; 
De Groot, K., Klein, C.P.A.T., (1990) "Handbook of Bioactive Ceramics", Vol. II-Calcium Phosphate and Hydroxylapatite Ceramics, 2, p. 3. , edited by T. Yamamuro CRC Press, Boston; 
Hollinger, J.O., Schmitz, J.P., Mizgala, J.W., Hassler, C., (1989) J. Biomed. Mater. Res., 23, p. 17; 
Cavalheiro, J., Branco, R., Vasconcelos, M., (1991) Proceedings of the 4th International Conference on Bioceramics, p. 205. , edited by W. Bonfield, G. W. Hastings and K. E. Tanner, London, UK Butterworth-Heinemann, Oxford; 
Santos, J.D., Reis, R.L., Knowles, J.C., Monteiro, F.J., Hastings, G.W., (1994) Biomaterials, 15, p. 5; 
Nery, E.B., Legeros, R.Z., Lynch, K.L., Kalbleisch, J., (1988) J. Dent. Res., 67, p. 178; 
Ellinger, R.F., Nery, E.B., Lynch, K.L., (1986) Int. J. Period. Restor. Dent., 3, p. 223; 
Legeros, R.Z., Daculsi, G., (1990) "Handbook of Bioactive Ceramics", Vol. II-Calcium Phosphate and Hydroxylapatite Ceramics, 2, p. 17. , edited by T. Yamamuro CRC Press, Boston
},
	month = {1996///},
	pages = {507 - 510},
	abstract = {Granules of a modified hydroxyapatite, glass-reinforced hydroxyapatite composite and commercial hydroxyapatite were implanted in rabbit tibiae. Histological studies were carried out after 1 and 2 months implantation periods using light and fluorescence microscopy. A much higher percentage of bone contact was developed for both the glass-reinforced hydroxyapatite composite and the modified hydroxyapatite when compared to commercial hydroxyapatite (89-91\% versus 66\%) after 2 months implantation. The mechanism of bone formation and growth around implants is discussed in terms of the influence of elements incorporated into these novel materials which are commonly found in bone tissues, such as Na, K and Mg, and the presence of a soluble β-tricalcium phosphate phase in the microstructure of the composite.},
	keywords = {animal experiment, animal tissue, article, Bone, Bone formation, bone growth, Calcium Compounds, calcium phosphate, Composite materials, Fiber reinforced materials, glass, Glass fibers, Glass reinforced hydroxyapatite, Granular materials, histology, hydroxyapatite, implant, Implants (surgical), Magnesium, Microstructure, Modified hydroxyapatite, nonhuman, Optical microscopy, ossification, Osteoapatite, Oxides, Phosphates, Physiological models, potassium, priority journal, rabbit, Rabbit tibiae, Sodium, tibia, X ray diffraction analysis},
	isbn = {09574530 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0029666749\&partnerID=40\&md5=48a404008151489ff92ea9bc191cf374},
	author = {Afonso, A. and Santos, J.D. and Vasconcelos, M. and Branco, R. and Cavalheiro, J.}
}
@article {2623,
	title = {In vitro calcium phosphate formation on SiO                    2-Na
                    2O-CaO-P
                    2O
                    5 glass reinforced hydroxyapatite composite: A study by XPS analysis
},
	journal = {Journal of Materials Science: Materials in MedicineJ. MATER. SCI. MATER. MED.},
	volume = {7},
	year = {1996},
	note = {Cited By (since 1996): 42Export Date: 21 November 2012Source: ScopusCODEN: JSMMELanguage of Original Document: EnglishCorrespondence Address: Santos, J.D.; FEUP, Rua dos Bragas, 4099-Porto Codex, PortugalChemicals/CAS: calcium phosphate, 10103-46-5, 13767-12-9, 14358-97-5, 7758-87-4; hydroxyapatite, 1306-06-5, 51198-94-8References: Ducheyne, P., (1987) J. Biomed. Mater. Res.: Appl. Biomater., 21 (A2), p. 219;Hench, L.L., (1989) J. Biomed. Mater. Res., 23, p. 685; 
Hench, L.L., (1991) J. Amer. Ceram. Soc., 7, p. 1487; 
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},
	month = {1996///},
	pages = {181 - 185},
	publisher = {Chapman \& Hall Ltd},
	abstract = {In-vitro apatite layer formation on the surface of a newly developed glass reinforced hydroxyapatite composite was characterized using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDXA). After 1 week soaking in an acellular simulated body fluid the composite surface was entirely covered by a Ca, P-layer, suggesting a bioactive behaviour. XPS binding energy results revealed that this surface layer was a carbonated and non- stoichiometric apatite with Ca/P ratio of 1.3. This apatite layer was composed of very fine needle-like crystallites. Comparative studies on a commercially available hydroxyapatite showed that a similar apatite layer was also formed on its surface.In-vitro apatite layer formation on the surface of a newly developed glass reinforced hydroxyapatite composite was characterized using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDXA). After 1 week soaking in an acellular simulated body fluid the composite surface was entirely covered by a Ca, P-layer, suggesting a bioactive behaviour. XPS binding energy results revealed that this surface layer was a carbonated and non-stoichiometric apatite with Ca/P ratio of 1.3. This apatite layer was composed of very fine needle-like crystallites. Comparative studies on a commercially available hydroxyapatite showed that a similar apatite layer was also formed on its surface.
},
	keywords = {article, Binding energy, Biocompatibility, Biodegradation, biomaterial, Calcium, calcium phosphate, Characterization, Composite materials, Composition, Energy dispersive x ray analysis, glass, Glass reinforced hydroxyapetite composite, hydroxyapatite, implant, In vitro calcium phosphate formation, Ionic concentration, molecular interaction, Nucleation, Phosphates, phosphorus, priority journal, Scanning electron microscopy, Surfaces, X ray analysis, X ray photoelectron spectroscopy},
	isbn = {09574530 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0030106254\&partnerID=40\&md5=725eba3e273e23b5c6519d07483495e8},
	author = {Santos, J.D. and Jha, L.J. and Monteiro, F.J.}
}
@article {2624,
	title = {Reinforcement of hydroxyapatite by adding P                    2O
                    5-CaO glasses with Na
                    2O, K
                    2O and MgO
},
	journal = {Journal of Materials Science: Materials in MedicineJ. MATER. SCI. MATER. MED.},
	volume = {7},
	year = {1996},
	note = {Cited By (since 1996): 49Export Date: 21 November 2012Source: ScopusCODEN: JSMMELanguage of Original Document: EnglishCorrespondence Address: Santos, J.D.; Dept. of Metallurgical Engineering, FEUP, University of Porto, Rua dos Bragas, 4099 Porto Codex, PortugalChemicals/CAS: hydroxyapatite, 1306-06-5, 51198-94-8; magnesium oxide, 1309-48-4, 1317-74-4References: Barney, V.C., Levin, M.P., Adams, D.F., (1986) J. Perio Dont., 57, p. 764;Legeros, R.Z., (1988) Adv. Dent. Res., 2, p. 164; 
Aoki, H., (1991) Science and Medical Applications of Hydroxyapatite, p. 165. , Takayama Press System Center, JAAS, Tokyo; 
Ducheyne, P., (1987) J. Biomed. Mater. Res. Appl. Biomater., 21, p. 219; 
Heughbaert, J.C., Bonel, G., (1986) Biological and Biomechanical Performance of Biomaterials, p. 9. , edited by P. Christel, A. Meunier and A. J. C. Lee Elsevier Science Publishers B.V., Amsterdam; 
Ellis, L.G., Nelson, D.G.A., Featherstone, J.D.B., (1988) J. Biomed. Mater. Res., 22, p. 541; 
Raemdonck, W.V., Ducheyne, P., Meester, P.D., (1984) Metal and Ceramic Biomaterials, p. 143. , edited by P. Ducheyne and G. W. Hashi CRC Press, Boca Raton, FL; 
Shors, E.C., Holmes, R.E., (1993) An Introduction to Bioceramics, p. 181. , edited by L. L. Hench and J. Wilson World Scientific, Hong Kong; 
Rey, C., (1990) Biomaterials, 11, p. 14; 
Evans, G., Behiri, J., Currey, J., Bonfield, W., (1990) J. Mater. Sci. Mater. Med., 1, p. 38; 
Rey, C., Fr{\`e}che, M., Heughebaert, M., Heughebaert, J.C., Lacout, J.L., Vignoles, M., Bioceramics 4, London, 1991, p. 57. , edited by W. Bonfield, G. W. Hastings and K. E. Tanner (Butterworth-Heinemann, London); 
With, G., Van Dijk, H., Hattu, N., Prijs, K., (1981) J. Mater. Sci., 16, p. 1592; 
Akao, M., Aoki, H., Kato, K., (1981) J. Mater. Sci., 16, p. 809; 
Santos, J., Knowles, J., Reis, R., Monteiro, F., Hastings, G., (1994) Biomaterials, 15, p. 5; 
Soltesz, U., Richter, H., Kienzler, R., (1987) High Technology Ceramics, p. 110. , Elsevier Science Publishers, B.V., Amsterdam; 
(1971) Determination Micrographique de la Grosseur du Grain Ferritique ou Aust{\'e}nitique des Aciers; 
Daculsi, G., LeGeros, R.G., Nery, E., Lynch, K., Kerebel, B., (1989) J. Biomed. Mater. Res., 23, p. 883
},
	month = {1996///},
	pages = {187 - 189},
	publisher = {Chapman \& Hall Ltd},
	abstract = {Commercial hydroxyapatite was reinforced by adding small amounts (2 and 4 wt\%) of P                        2O
                        5-based glasses during its sintering process. The composites prepared had a chemical composition closely related to the mineral part of bone tissues in terms of trace elements usually detected, such as Na, K and Mg. X-ray diffraction analysis (XRD) showed that the glass reinforced-HA composites were composed of a HA matrix and variable amounts of tricalcium phosphate phase, depending on sintering temperature and glass composition. These composites were shown to have much higher biaxial bending strength than sintered HA, 107 MPa for Ha/2\% of 35P
                        2O
                        5-35CAO-10Na
                        2O-10K
                        2O-10MgO glass composite and 28 MPa for sintered HA. The presence of β-tricalcium phosphate in the microstructure of the composites is an important factor in the reinforcement process.
Commercial hydroxyapatite was reinforced by adding small amounts (2 and 4 wt\%) of P
                        2O
                        5-based glasses during its sintering process. The composites prepared had a chemical composition closely related to the mineral part of bone tissues in terms of trace elements usually detected, such as Na, K and Mg. X-ray diffraction analysis (XRD) showed that the glass reinforced-HA composites were composed of a HA matrix and variable amounts of tricalcium phosphate phase, depending on sintering temperature and glass composition. These composites were shown to have much higher biaxial bending strength than sintered HA, 107 MPa for Ha/2\% of 35P
                        2O
                        5-35CaO-10Na
                        2O-10K
                        2O-10MgO glass composite and 28 MPa for sintered HA. The presence of β-tricalcium phosphate in the microstructure of the composites is an important factor in the reinforcement process.
},
	keywords = {article, Bending strength, Bone, chemical composition, Composite materials, Composition, Composition effects, glass, Glass composition, Glass reinforced hydroxapatite composite, hydroxyapatite, implant, Magnesium Oxide, metal oxide, Microstructure, molecular dynamics, Phosphates, potassium derivative, priority journal, Sintering, Sintering temperature, sodium derivative, Thermal effects, Trace Elements, Tricalcium phosphate phase, X ray diffraction},
	isbn = {09574530 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0030108677\&partnerID=40\&md5=e9c978c3e018a1dd2db9b534ef00ea1b},
	author = {Santos, J.D. and Silva, P.L. and Knowles, J.C. and Talal, S. and Monteiro, F.J.}
}
@article {2634,
	title = {Liquid phase sintering of hydroxyapatite by phosphate and silicate glass additions: Structure and properties of the composites},
	journal = {Journal of Materials Science: Materials in MedicineJ. MATER. SCI. MATER. MED.},
	volume = {6},
	year = {1995},
	note = {Cited By (since 1996): 41Export Date: 21 November 2012Source: ScopusCODEN: JSMMEdoi: 10.1007/BF00120303Language of Original Document: EnglishCorrespondence Address: Santos, J.D.; INEB-National Inst. Biomedical Engn., Department Metallurgical Engineering, FEUP, University of Porto, Rua dos Bragas 4099-Porto Codex, Portugal},
	month = {1995///},
	pages = {348 - 352},
	publisher = {Chapman \& Hall Ltd},
	abstract = {Phosphate- and silicate-based glasses were added to hydroxyapatite in order to improve its mechanical properties and to fabricate composites with different degrees of bioactivity. A strong chemical bonding was obtained between hydroxyapatite and the phosphate-based glasses leading to samples approaching theoretical density, according to density measurements and scanning electron microscopy. Bioglass{\textregistered} additions led to the formation of a complex calcium phosphate silicate which hampered the reinforcement process. The fracture toughness of the hydroxyapatite-glass composites was shown to be within the 1.1-1.2 MPam(1/2) range, which is double that determined for sintered hydroxyapatite. A 2 μm thick apatite layer was observed on the surface of the hydroxyapatite-glass composites after 48 h immersion in a simulated human blood plasma, whereas only a few apatite crystals were detected on sintered hydroxyapatite after 7 days immersion. From the results obtained we anticipate that the composites might show a higher rate of bone bonding, leading to enhanced bioactivity.Phosphate- and silicate-based glasses were added to hydroxyapatite in order to improve its mechanical properties and to fabricate composites with different degrees of bioactivity. A strong chemical bonding was obtained between hydroxyapatite and the phosphate-based glasses leading to samples approaching theoretical density, according to density measurements and scanning electron microscopy. Bioglass
                        (R) additions led to the formation of a complex calcium phosphate silicate which hampered the reinforcement process. The fracture toughness of the hydroxyapatite-glass composites was shown to be within the 1.1-1.2 MPa m
                        1/2 range, which is double that determined for sintered hydroxyapatite. A 2 μm thick apatite layer was observed on the surface of the hydroxyapatite-glass composites after 48 h immersion in a simulated human blood plasma, whereas only a few apatite crystals were detected on sintered hydroxyapatite after 7 days immersion. From the results obtained we anticipate that the composites might show a higher rate of bone bonding, leading to enhanced bioactivity.
},
	keywords = {Adhesion, article, Bioactivity, Bioglass, Biomaterials, Bone, bone prosthesis, calcium phosphate, chemical binding, Chemical bonds, chemical composition, Chemical structure, Complex calcium phosphate silicate, Composite materials, crystal, density, Density measurement (specific gravity), glass, Human blood plasma, hydroxyapatite, Liquid phase sintering, Mechanical properties, Mechanics, phosphate, Phosphates, plasma, priority journal, Scanning electron microscopy, silicate, Silicates, Sintering, Structure (composition), surface property, thickness},
	isbn = {09574530 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0029311049\&partnerID=40\&md5=433498e286bfad74a296d1fafc50c223},
	author = {Santos, J.D. and Reis, R.L. and Monteiro, F.J. and Knowles, J.C. and Hastings, G.W.}
}
@article {2635,
	title = {Surface modifications of glass-reinforced hydroxyapatite composites},
	journal = {BiomaterialsBIOMATERIALS},
	volume = {16},
	year = {1995},
	note = {Cited By (since 1996): 24Export Date: 21 November 2012Source: ScopusCODEN: BIMADdoi: 10.1016/0142-9612(95)91124-HPubMed ID: 7492715Language of Original Document: EnglishCorrespondence Address: Santos, J.D.; Dept Metallurgical Engineering, FEUP, University of Porto, Rua dos Bragas 4099-Porto Codex, PortugalChemicals/CAS: Biocompatible Materials; Calcium, 7440-70-2; Glass; Hydroxyapatites; Phosphorus, 7723-14-0; Silicon, 7440-21-3; Sodium, 7440-23-5},
	month = {1995///},
	pages = {521 - 526},
	publisher = {Butterworth-Heinemann Ltd},
	abstract = {Surface modifications of glass-reinforced hydroxyapatite composites immersed in a simulated physiological solution were studied using X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. In the first stages of the apatite formation process, calcium and silicon ions were leached out from the surface of the composites. After 12 days of immersion, apatite crystals were detected on the surface indicating bioactive behaviour. Sodium ions attributed to sodium sulphate were also found in the apatite layer. Bound water on the surface also increased with immersion time.Surface modifications of glass-reinforced hydroxyapatite composites immersed in a simulated physiological solution were studied using X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. In the first stages of the apatite formation process, calcium and silicon ions were leached out from the surface of the composites. After 12 days of immersion, apatite crystals were detected on the surface indicating bioactive behaviour. Sodium ions attributed to sodium sulphate were also found in the apatite layer. Bound water on the surface also increased with immersion time.
},
	keywords = {Apatite, article, Bioactive glass, Biocompatible Materials, Biomaterials, Calcium, chemical composition, Composite materials, Electron Probe Microanalysis, glass, Glass reinforced hydroxyapatite composites, Hydrogen-Ion Concentration, hydroxyapatite, Hydroxyapatites, immersion, Ions, Leaching, Microscopy, Electron, Scanning, Phosphates, phosphorus, priority journal, Scanning electron microscopy, Silicon, Sodium, sodium chloride, sodium sulfate, Spectrometry, X-Ray Emission, Spectroscopy, Surface modification, Surface Properties, surface property, Surface treatment, Water, X ray, X ray photoelectron spectroscopy, X ray spectroscopy},
	isbn = {01429612 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0029294502\&partnerID=40\&md5=2694e1944afd0945ac391ba41c4ec7b5},
	author = {Santos, J.D. and Jha, L.J. and Monteiro, F.J.}
}
